LFX Engine -- Unrefined

[dwightlooi]

OK, got to drive a LFX equipped Camaro for the first time. And, I am sad to report that there had been no significant improvement in the refinement of the engine (compared to the 312hp LLT). The engine is still plagued by the most unpleasant acoustics I can bear. At idle it makes a muted, diesel like clatter. At low rpms between 1000~3000 the engine makes a groany gggaaarrrr. It all gets somewhat drowned out by about 4000~5000 rpm as the rest of the engine noises catches up. To a certain degree, cruising noise on the freeway isn’t bad because the wind noise, tire noise and everything else help mask the utterly uninspiring engine note. But on local streets pulling modestly from a light the GM 3.6 DOHC DI V6 was and continues to be perhaps the most unrefined sounded engine I have experienced.

While I applaude the performance of the powerplant on paper, this is possibly the greatest step backwards in refinement GM has taken in years. Forget about class leading refinement from the BMW straight sixes, the Lexus V6es or, heck, the Acura V6es. If you compare it to the 3.9 pushrod, 3.5 pushrod, 3.6 DOHC (non-DI) or the grand old 3.8 it is clearly and unmistakably much worse in the low frequency clatter department. Feels and sounds like a quick revving tractor engine if that’s possible.

I believe that this is the biggest refinement issue GM needs to solve if it wants to play in the luxury league with Cadillac and Buick. This engine character will turn off more mainstream buyers than 90hp/liter will attract drinkers of technobabble.

I believe the problem is inherent to solenoid direct injectors. And, the isolation that GM put in the LFX simply isn’t cutting it. In fact, it sounded no better than the LLT – at least not to me. No, I didn’t drive both back to back and memory can be a little deceptive on sounds when the events are months apart. But, it was clearly and convincingly better when they need it to be.

The solutions are there, however GM’s willingness to embrace them may or may not be there. Toyota/Lexus went to a dual injection system specifically for this reason – port injection for idle and low rpms with direct injection kicking only under high load and engine speeds. VW-Audi went with Piezo direct injectors in lieu of solenoid injectors.

[Drew Dowdell]

While I agree on the uninspiring engine note (for a Camaro), I don't think I've ever heard the clatter to which you refer.

[hyperv6]

The clatter has been there from tha start and if anything is better since they have insulated the HP fuel pump. The sound is more noted out side but most people do not notice or even complain. The reason most do not complain as most of the cars with this engine are very quiet inside and they do not notice with the radio on.

I expect GM is already working with suppliers on quieter injectors.

While I do agree the engine needs some upgrades I do not find it nearly as bad as some like to make it. Compared to my Gen III 3800 SC it feels damn well refinded.

Could it be better yes is it that bad no.

[dwightlooi]

The clatter has been there from tha start and if anything is better since they have insulated the HP fuel pump. The sound is more noted out side but most people do not notice or even complain. The reason most do not complain as most of the cars with this engine are very quiet inside and they do not notice with the radio on.

I expect GM is already working with suppliers on quieter injectors.

While I do agree the engine needs some upgrades I do not find it nearly as bad as some like to make it. Compared to my Gen III 3800 SC it feels damn well refinded.

Could it be better yes is it that bad no.

Unfortunately, I came off feeling that it was pretty bad. This engine is not going to cut it as far as impressing luxury buyers of the CTS and ATS. At least not in the refinement department when they cross shop a Lexus, BMW, or Acura.

[smk4565]

I have driven the 3.6 with and without DI in the CTS, but that was before the LFX upgrade. I thought the problem with the engine was above 4,000 rpm it sounded harsh, thrashing and wheezy almost. It was like the engine was resisting higher revs and made a lot of unpleasant sounds so you would slow back down. It is a far cry from a BMW engine.

In regard to the 2.0T, reviews of the ATS say that engine feels more like 230 hp than 270 hp. So you wonder if it really has 270 hp to begin with, because the 328i outruns it with ease. But BMW engines are severely under rated in horsepower.

I think Cadillac needs and all new turbo 4, all new V6, all new turbo six and all new transmission. What they have isn't matching up to the Germans. Which is a shame because the car magazines love the ATS's chassis and rip it on engine and transmission.

[Robert Hall]

Probably needs more sound deadening and a quieter exhaust.

[chevelle454]

I don't have any clatter with my 2012 Impala or the 2012 CTS Coupe that I drove for a while.

[vonVeezelsnider]

The only issue I had with a strange noise in the 2012 Impala 3.6 I drove is a weird whistling noise when the engine spools up for a higher rev (ie to pass or merge), otherwise more refined and well behaved, although slightly less relaxed than the 3.5 pushrod which I have become so familiar with and fond of.

[dwightlooi]

Perhaps Clatter is not the right word... the engine sounds at lower RPMs have a diesel like "gggrrroooccc" to it. GM's port injected V6es don't have that -- Pushrod or DOHC. The 3.5 and the 3.9 for instance are quieter engines albiet somewhat less rev willing. If you wind down the windows you hear a tock-tock-tock-tock drone from the injectors too. But this is not a responsiveness issue, this is a refinement issue. At this rate, they are better off with 40 hp less and using Port Injection. Drove a Saturn Aura 3.6 once... didn't have these stupid low rpm acoustics. Wind it out to 5000+ rpm and it doesn't sound bad really... it's kinda a baaawwaaahhhhhh with a baritone exhaust note. Not exactly a VTEC like rasp or a turbine like whirl, but not objectionable.

Edited October 23, 2012 by dwightlooi

[hyperv6]

DI engines have been noisy from the start. They if anything have gotten more quiet. While DI helps in power and MPG it always has had issuws with the noise. The injectors pushing up to and over 2000 PSI to inject fuel into high compression cylinders work very hard and slam shut making a mechanical sound that is not plesent to those on the sidewalk but has little effect to anyone inside.

My 3.0 in the GMC is quiet and has little notice inside but it growls much like a N start as the revs climb. WHile the GMC outside is fairly quiet the HHR does make a lot of more clatter. THis is a case of 08 vs 12 changes. Also the Ecotec was redesigned recently to take advantage of new ways to silnce the engine.

Like I said the DI engines could be better but ealiy 90% of those who own them will and have complained more about tire noise. The two forum sites I visit for my two vehicles I have seen little to no complaints on the engine sounds. Do they want more power and MPG ...yes but sound issues are very rarely brought up even compared to other makes and models.

As for the tire noise it is a big complain with many owners with replacment tires.

One thing too is a V6 and 4 cylinder are difficult to make sound good with most models. Of all the V6 cars I have ever had the 60 degree 2.8 in my Fiero is the only one that had a good exhaust note. The one advantae a V8 has is sound and there are few smaller engines that can reproduce that. Same for a V12 on the track vs a V8 as a 12 has a amazing sound.

As for my SS I will live with the factory exhaust as I hate the sound of a 4 in most cases with a more open exhaust. The Fart can sound is just not amusing to me.

Edited October 23, 2012 by hyperv6

[G. David Felt]

Probably needs more sound deadening and a quieter exhaust.

I have wondered why GM does not use the Buick Quiet steel technology on top of their normal sound deadening material to get an ultra quiet ride.

[dwightlooi]

Probably needs more sound deadening and a quieter exhaust.

I have wondered why GM does not use the Buick Quiet steel technology on top of their normal sound deadening material to get an ultra quiet ride.

Actually they do. And it's actually quiet effective even in the Malibu.

[CanadianBacon94]

This clicking sound?

about 6 :20

Edited October 23, 2012 by CanadianBacon94

[G. David Felt]

Video is great, I can barley hear of what I think is the engine clicking noise until they open the hood, would not be an issue for me or people I know.

Couple things that seem to really stick out on this video is that crazy big fat semi pillar just after the A pillar, I see why they did the little window, but crazy. I do love the way they did the hood with the insulation, very clean and nice. I do find the overspeed warrning to be pretty funny. Exhaust does sound wimpy in my opinion. Needs to be tuned better.

While we can all nit pick a car, this car is still pretty awesome and I think most will find it a pleasent ride.

[Guest Ado90]

OK, got to drive a LFX equipped Camaro for the first time. And, I am sad to report that there had been no significant improvement in the refinement of the engine (compared to the 312hp LLT). The engine is still plagued by the most unpleasant acoustics I can bear. At idle it makes a muted, diesel like clatter. At low rpms between 1000~3000 the engine makes a groany gggaaarrrr. It all gets somewhat drowned out by about 4000~5000 rpm as the rest of the engine noises catches up. To a certain degree, cruising noise on the freeway isn’t bad because the wind noise, tire noise and everything else help mask the utterly uninspiring engine note. But on local streets pulling modestly from a light the GM 3.6 DOHC DI V6 was and continues to be perhaps the most unrefined sounded engine I have experienced.

While I applaude the performance of the powerplant on paper, this is possibly the greatest step backwards in refinement GM has taken in years. Forget about class leading refinement from the BMW straight sixes, the Lexus V6es or, heck, the Acura V6es. If you compare it to the 3.9 pushrod, 3.5 pushrod, 3.6 DOHC (non-DI) or the grand old 3.8 it is clearly and unmistakably much worse in the low frequency clatter department. Feels and sounds like a quick revving tractor engine if that’s possible.

I believe that this is the biggest refinement issue GM needs to solve if it wants to play in the luxury league with Cadillac and Buick. This engine character will turn off more mainstream buyers than 90hp/liter will attract drinkers of technobabble.

I believe the problem is inherent to solenoid direct injectors. And, the isolation that GM put in the LFX simply isn’t cutting it. In fact, it sounded no better than the LLT – at least not to me. No, I didn’t drive both back to back and memory can be a little deceptive on sounds when the events are months apart. But, it was clearly and convincingly better when they need it to be.

The solutions are there, however GM’s willingness to embrace them may or may not be there. Toyota/Lexus went to a dual injection system specifically for this reason – port injection for idle and low rpms with direct injection kicking only under high load and engine speeds. VW-Audi went with Piezo direct injectors in lieu of solenoid injectors.

i dunno what your on about chief... i have the LFX in my holden and its alot better then my older model with the LLT, shes got 2,000 miles on it so far and no dramas when the car is idle you dont even know it on its thats smooth and its more quiter then a baby in a deep sleep and the engine note with a decent exhaust is unbelieveable... when she wants to take off she will without putting too much labour on the engine in low rev range... maybe try broaden your test of different cars with the LFX... ive driven a couple of my mates holden with these engines and there is nothing to complain about all the same with comfort and power for a 4188lb ute lol

[Intrepidation]

The 3.6 sounds awesome with the right exhaust (Corsa). Friend of mine got it for his Camaro and it sounds very good.

[riviera74]

A refined Camaro? Since when? Maybe it is a bias from the F-body era, but a Camaro is not supposed to be refined..... is it?

[hyperv6]

The 3.6 sounds awesome with the right exhaust (Corsa). Friend of mine got it for his Camaro and it sounds very good.

Just had a friend put a Corsa on a new Camaro V6 and I was afraid it would not sound right but I was wrong. The Corsa came out very good.

Also the engine in that car is no more unrefined than the V8. I found nothing to be objectionable.

GM with each model and each use of this engine has refind the noise issue related to it. Yes at the beginning it did make some odd noise mostly outside but since the first CTS model year it has proven not problematic.

Lets put it this way the forums are now swapped with complaints.

[G. David Felt]

Complaints or Complements? I guess I do not hang out in the same Forums as I do not see the complaints about the V6 clicking noise. I do see and hear lots of complements on how well GM is executing compared to days of old pre Bankrupt.

[hyperv6]

Sorry I was late for work it should have read NOT swamped with complaints.

There was some talk of the clicking when the engine cam to market but as the noise has toned down with changes as has the talk. Also there was issues with the soot in the tail pipes and black smoke at start up at times. now that people know it is normal no one speak of it anymore.

[Drew Dowdell]

I still say the 3.6 in the LaX and Cadillacs and Lambdas is just fine thanks. I don't find it unrefined at all. It is a lot less of a growler than the VQ. I've recently had a pathfinder and JX (both rentals) and while I was on the highway I really wanted to shout "OH ENOUGH ALREADY!" at the constant growl of their engines.

[Guest Ernie]

I was actually very pleased when I tried out an LFX. You're going to get that slight clicking noise due to the injectors, there's really no avoiding that. It's more shocking that it's as quiet as it is, absolutely inaudible inside the vehicle. Admittedly, I didn't try a Camero but a 2012 Impala. I can't imagine there being a major difference, but even with what I assume was the stock exhaust I had absolutely no problem with the exhaust note, either. Honestly, I really, really liked it. Our entire group did!

[Guest ponchoman49]

I just purchased a 2013 Impala LT with the new LFX and I have to agree that this engine is less refined sounding than my prior 2008 3900 AFM motor. It clunks into life when I start it. It growls upon acceleration and it even vibrates the dash at hot idle sometimes. It feels a bit vibratory when you take off from a traffic light too. Of course it didn't exhibit these traits on the test drive when it was 85 degrees outside. The noise is much worse in colder temps. I am also noticing a slight clunking noise when the herky jerky 6 speed transmission upshifts and downshifts at times so that makes me wonder if my 24k mile prior rental was abused and has a broken mount or something. It goes in to service this week. The one thing this engine doesn't do is the cold Di injector tick so I am grateful for at least that.

[Guest Hunter]

To put this politely, You are an idiot. You're comparing a Camaro to Lexus. A sports car to a luxury car. Wtf? Head2head, motortrend, car and driver...ANY magazine, blog, etc who has compared the Camaro to its TRUE peers (mustang/challenger) literally says the exact opposite. They call it a "gentlemans sports car" and say it is "impressively refined" due to its LACK of road noise and it's great Responsiveness/handling where mustangs are built cheaply and are rough and loud, and challengers may as well have 4 doors. The owner of Hypertech (who make tuners for cars) calls the LFX "one of the best engines in history straight from the factory". It took Hypertech over 900 dyno runs to get enough information to improve the engine. And that "chatter" you whine about is a high pressure fuel system. Do your research. Injectors that can pump out 109 lb/hr are going to make some noise. Yeah it's a little annoying but how else can you combine 323 hp with 30 mpg in a car that's heavy and solid enough to have perfect 5 star safety ratings? You have to go hi tech. The only logical point you made in the article was that no, the exhaust isn't very mean sounding. Here's a tip....go to Amazon and purchase A) magnaflow muffler or B) x pipe or C) cold air intake. Either of these can be found for less than $100 and installed easily. My 2015 Camaro 3.6 has a cold air intake that took 30 minutes to install and now under light throttle she has a mean little growl and when I open her up she roars like any v8 out there. Take a second to think that that little 3.6 liter v6 is pushing more power than the 4.6 liter v8 mustang GT did until 2011 when Ford finally switched to a 5.0. And I'm not even going to compare it to the v6 challenger....a Honda Civic could outrun one of those.